attn Mr. Hobbs

you seem to be the resident body man. I am considering making a fiberglass bumper and hood for my truck. Is it hard to make a mold off of the excisting steel one? They did it on powerblock tv last week and made it look easy. But looking for real world experience.
Thanks, Dave

Dave ,I've never made one off a steel one. Randy Moore has studied this. He's the guy to talk to. I've got some Chevy buddies down the road who've done it, and made some awesome looking pieces. They say it's easy? I've repaired lots of fiberglass ,but just never got into molding it. Sorry I can't help you on this.

Here is a good site to read up on different techniques , http://www.compositescentral.net/forumdisplay.php?f=9&page=2&order=desc

I have not molded any big things just small stuff experimenting so far. I did get into an in depth discussion with the gentleman that built my car body about the dos and dont's but thats it.

Lots of video's on you tube also.

I have read where people have used the inside of an original steel bumper as the mold it's self.

The up-side is you do away with the mold making step (and thus end up using less materials), but it's not a 100% "perfect" reproduction. Since you're using the inside of the bumper as the mold, the finished 'glass product is a slightly smaller scale copy. And there is a chance that distinctive lines on the outside of an original steel bumper might not be as sharply "defined" on a 'glass copy pulled from the inside of the original bumper, but it still could be damn close.

I guess the same procedure could also be used for making a 'glass hood too (inside of the steel hood's skin as the mold). But you would have too gut the hood of all the inner structure & build a framework to support/keep the shape the remaining flimsy hood outer skin.

It is easier to use the exterior of the part and make a fiberglass mold of that surface. You then have a female mold to make new parts from that are dimensionally accurate as the old steel part. But depending on the part size and shape, a two piece mold might be better.

There are a few ways to pop out glass parts depending on what you are trying to accomplish.

There is a thread/topic over off www.theturboforums.com and corral covering CF, but it's the same thing to make glass parts.

The only thing I really can add or stress is to start with the best part you can find and make sure it is beyond perfect.

Brian